Functional magnetic resonance imaging in a low-field intraoperative scanner

Area of Science:

• Neuroimaging
• Medical Physics
• Neurosurgery

Background:

• Functional magnetic resonance imaging (fMRI) is crucial for surgical planning and navigation.
• Current fMRI applications primarily rely on high-field MRI, limiting intraoperative use.
• The study investigates the potential of low-field intraoperative MRI (iMRI) for fMRI acquisition.

Purpose of the Study:

• To assess the feasibility of acquiring fMRI data from the motor cortex using a low-field iMRI system.
• To compare the performance of a low-field iMRI with a high-field MRI for motor cortex fMRI.
• To evaluate the potential of iMRI-based fMRI for real-time intraoperative functional imaging.

Main Methods:

• Five healthy volunteers underwent fMRI using a 0.12-tesla iMRI and a 3-tesla MRI.
• Motor paradigms included finger-tapping and breath-holding tasks, alternating with rest.
• Statistical analysis involved cross-correlation, cluster techniques, and jackknife resampling for comparison.

Main Results:

• Both 0.12-tesla and 3-tesla imagers successfully detected motor cortex activation (p < 0.02) in all subjects.
• Activation patterns were confined to the sensorimotor cortex, with no off-target signals.
• Resampled correlation coefficients showed comparable distributions between the two scanners, indicating similar data quality.

Conclusions:

• Accurate fMRI of the motor cortex is feasible using a low-field iMRI system.
• iMRI-based fMRI can be acquired immediately before or during surgery.
• This technology enhances iMRI utility by providing updated, intraoperative functional imaging, mitigating brain shift issues.